Switch Level 110/220VAC

For control of ordinary purified water or sewage water .

Supply voltage: 100, 110, 120, 200, 220 or 240 VAC; 50/60 Hz

Operating voltage range: 85% to 110% of rated voltage

Ideal for level control of any conductive liquid Both general-purpose and panel-use models available Incorporates an arrester for surge and induced lightning protection Wide range of models: Long-distance, high- and low-sensitivity, two-wire, etc. LED indicator for quick operation check Conforms to EMC/IEC standards (61F-GP-N/-N8/-GPN-V50) UL/CSA approved (61F-GP-N8/-GPN-V50)

A pump is usually connected to a contactor, which in turn is connected to the Controller contact outputs. The Level Controller would automatically operate the pump, to control the liquid level in the tank. However, in practice, with only two electrodes, ripples on the surface of the liquid cause the Controller to jump and start, shortening pump (and other equipment) life. This problem can be solved by adding another electrode to form a self-holding circuit. The additional electrode, E2, is connected in parallel with E1, as shown below.

Unlike ordinary level switches that use a float for level detection, the 61F Floatless Level Controller uses electrodes to electrically detect the liquid level. The following figures illustrate this simple operating principle.

Relay contacts a E1 Magnetic contactor (To) E3 No current flows between E1 and E3.

When electrode E1 is not in contact with the conductive liquid, the electrical circuit is open, and no current flows between electrodes E1 and E3. Consequently, relay X does not operate. Relay X's NC contacts (normally closed, b in the figure) remain closed. However, when liquid is supplied to the tank, so that the liquid contacts or immerses E1, the circuit closes. Relay X operates, and electrical devices connected to the NO (normally open, a in the figure) contacts of the relay begin operation.

Relay contacts a E1 Magnetic contactor (To) E3 Current flows between E1 and E3.

As shown in the above figure, when the holding circuit relay is energized, contact a2, its NO contact, is closed. The electrical circuit made through the liquid and the electrodes is then retained by E2 and E3, even when the liquid level falls below E1, as long as contact a2 is closed. When the liquid level falls below E2, the circuit made through the electrode circuit opens, which de-energizes relay X, thus closing the NC contact of X. Operating as simply as it does, possible applications of the Floatless Level Controller are virtually endless. Not only liquid level control is possible, but such applications as leakage detection, object size discrimination, and many other problems may be solved by one of the reliable 61F Floatless Level Controllers.

To use a 61F Conductive Level Controller, the 61F itself, Electrode Holders, and Electrodes are required.

Select from the capability, function, and size to suit the application. 61F Refer to the following Controller selection guidelines. Basic configuration Electrode Holders Select from the characteristics, application examples, and shape. Refer to page 66 for cautions about the Electrode Holders. Select according to operating conditions and shape. Electrodes Refer to pages to 67 for cautions about the Electrodes.

61F Controller Cermet wire is used in the transformer to prevent accidents by short-circuiting.

Relay Unit Incorporates a transistor-based control circuit and output relay. One to five Relay Units are used, depending on the application.

Electrode Holder/Electrodes Many materials, sensitivities and mounting variations are available.
Water supply source M: Electrical Motor P: Fluid Pump M P
Standard Model Plug-in Model Compact Plug-in Model
When there is sufficient mounting space. When monitoring operation through LEDs.

Item A t Automatic ti water t supply l and d drainage d i control l G1 Automatic water supply (idling prevention)

Automatic water supply (abnormal shortage alarm)
Automatic pump operation (constant water level)
Compact Plug-in Model Standard Model Plug-in Model
G2 Automatic water supply and drainage control (abnormal water increase alarm)